The Battle for Castle Kvatch

After completing the Breaking the Siege of Kvatch quest, this mission becomes available. You can begin it by talking to Savlian again and telling him you're ready to fight to win back the castle. Follow him through to the next courtyard.

If you do this quest after leveling up, the enemies will be much stronger than Savlian and will knock him out in a single hit. Luckily, he can't die and he'll recover quickly and continue fighting alongside you. Help him clear out the enemies in the area. When you're done, talk to Savlian. He'll tell you to go back into the Chapel and speak with Berich Inian.

Follow Berich down into the Undercroft. You now have a large squadron of Imperial guards and Berich to fight the slew of enemies you'll face. If Berich Inian dies, it is your responsibility to get the guard house key off of his body and continue on alone.

Go out of the basement through the only remaining door and you'll find more nasty demons to fight. If you have to, retreat back to the relative safety of the basement (though some enemies might follow you). You occasionally will get a respite where you can rest on one of the bedmats to heal. Also, there is a ledge just across from the well where you come out that acts as a nice sniping perch once all of the ranged enemies have been taken care of.

Once you've cleared out the area, start heading to the north. More enemies are waiting for you as you approach your target. Once again, there are plenty of perches around for you to sit atop of and wear down your targets.

After clearing the area travel to the north until you find the Castle Kvatch passage way which is a small sewer entrance on the ground. Follow the passageway to the ladder at the other end of the tunnel. Once in Kvatch activate the gate lever and Savlian and his men will rush into the castle. There is a hoard of enemies to be disposed of inside, then move further into the Kvatch Castle Great Hall.

The Great Hall is also filled with enemies, speak with Savlian when they are destroyed and he will tell you to advance into the castle alone and find the Count. Continue on into the Great Hall. You'll be faced with some battles as soon as you go through the door, only this time you'll have to fight them by yourself making them a little bit more difficult. When the coast is clear, look for a copy of the book Dance in Fire on the right placed on a table. Read it to increase your Acrobatics.

The side passages in the Great Halls are dead ends but are filled with ingredients and a bed. After plundering the halls enter the Count's quarters and face more enemies. When the battle ends, look on the ground and you'll see the dead body Ormellius Goldwin. Search him to update the journal. Grab his signet ring as proof that he is dead and return it to Savlian. As a reward, you'll get the Kvatch Cuirass, which is enchanted with fortify Endurance and Strength at 5 points each.

Tierra will lead the survivors outside of the town. You can meet them just outside the gates. Speak to Martin and he will agree to follow you to Weynon Priory.